This invention relates to drag reduction materials and the method of making such materials and more particularly to a method of making improved molded drag reduction coating formulations which inhibit the degradaton of drag reduction properties of high molecular weight polymers such as polyethylene oxide.
The present drag reduction systems usually uses the proccess of injecting the drag reduction slurries or solutions into the boundary layer. This requires equipment for storage, dissolving pumping and ejecting metered quantities of a drag reduction material into and not past the boundary layer of a moving vehicle such as a torpedo traveling at various speeds and depths. The use of aforementioned mixing and ejection equipment inherently generates undesirable noise and requires perforation of the surface of the vehicle. On the other hand, the use of coatings for drag reduction is a one shot process that can be easily applied directly to the pertinent hardware such as a torpedo. However, the use of heat and pressure treatments used to mold the powder of high molecular weight polymers into coatings deteriorates appreciably the drag reduction and noise reduction properties of the polymers. Consequently, it is desirable to use molded coatings for drag reduction which eliminates the inherent noise generated by the mixing and ejection equipment and to prevent the deterioration of the drag reduction capabilities during the heat and pressure treatment of high polymer powders used in the process of molding such coatings.